The present invention relates to an electromagnetically operated shutter mechanism for use in an optical image producing apparatus, such as a photographic camera or a copying machine, of a type which necessitates a shutter mechanism for selectively closing and opening an exposure aperture provided in the apparatus.
The copending application Ser. No. 725,201, filed on Sept. 22, 1976, now U.S. Pat. No. 4,121,235 the invention of which has been assigned to the same assignee of the present invention, discloses an electromagnetrically controlled shutter mechanism. According to the above described copending application, the shutter mechanism for selectively closing and opening an exposure aperture through which, during opening of the aperture, the incoming light is allowed to pass therethrough, said shutter mechanism substantially comprises, at least shutter member supported in position for movement between an inoperative position, in which the exposure aperture is closed, and an operated position in which the exposure aperture is opened, at least one permanent magnet, a substantially elongated carrier member having the permanent magnet rigidly mounted on one end portion thereof, the other end portion of said carrier member being connected to the shutter member, a solenoid coil supported in position to surround the elongated carrier member and circuit means. The circuit means includes first and second circuit components operable in opposed phase relationship to each other and electrically connected to said solenoid coil. The first circuit component during its operation feeds an electric current from a D.C. power source so as to flow through said solenoid coil in one direction, while the second circuit component during its operation feeds the electric current so as to flow through said solenoid coil in the opposite direction.
The permanent magnet is so positioned that, during the operation of the first circuit component, the shutter member is moved from the inoperative position towards the operated position by the effect of a magnetic force developed between the permanent magnet and the solenoid coil then energized by the current flowing in the one direction, and, during the operation of the second circuit component, the shutter member is returned from the operated position towards the inoperative position by the effect of a magnetic force developed between the permanent magnet and the solenoid coil then energized by the current flowing in the opposite direction.